乘兴

tā chéng xìng zuò le yī shǒu shī

她乘兴作了一首诗。

She improvises a poem while in a joyful mood.

chéng xìng yín shī

乘兴吟诗

chant a poem when one is happy

chéng xìng ér lái xìng jìn ér fǎn

乘兴而来，兴尽而返

arrive in high spirits and depart after enjoying oneself to one's heart's content

yǒu duō shǎo péng you jīn wǎn huì chéng xìng ér guī

有多少朋友今晚会乘兴而归？

How many people are gonna get some tonight?

tā cháng cháng jiǔ zuì hòu yī biān hū jiào yī biān kuáng zǒu chéng xìng ér huī háo

他常常酒醉后一边呼叫一边狂走，乘兴而挥毫。

He usually wrote for enjoyment after drinking, at the same time shouting and walking about.